Kiev, Ukraine ? Viktor Yushchenko will be sworn in Sunday as president of Ukraine, completing his “Orange Revolution” after weeks of political turmoil in which he defeated the Kremlin-backed candidate at the polls and survived a mysterious poisoning plot.

Lawmakers on Thursday hurriedly scheduled the inauguration in a decision that came hours after Yushchenko cleared the last of a series of legal obstacles that had arisen since the Dec. 26 election, including an appeal filed in the Supreme Court by loser Viktor Yanukovych.

Yanukovych, the former prime minister, had been supported by the Kremlin over Yushchenko, who aims to bring Ukraine closer to the European Union and NATO. But Russian President Vladimir Putin issued quick congratulations to Yushchenko, whose team said he would make a working visit Monday to Moscow.

On state television, Yanukovych predicted Yushchenko would be unable to maintain good relations with Russia and he declared he would stay in politics to lead the opposition.

“I’ll do everything I can to restore justice,” he said. “The ‘orange nightmare’ will not last long.”

The huge pro-Yushchenko demonstrations in Kiev, with many people wearing his orange campaign colors, arose after the Nov. 21 election in which Yanukovych was declared the winner. The Supreme Court annulled that result because of widespread fraud, and Yushchenko won the Dec. 26 court-ordered rerun balloting by about 8 percentage points.

As Yanukovych’s chances of overturning the results appeared to weaken in recent days, his supporters set up tent camps in several cities in eastern Ukraine, echoes of the once-enormous pro-Yushchenko camp in downtown Kiev.

Yanukovych on Thursday called for the camps to be taken down. But state television broadcasts from several of the cities indicated that crowds of his supporters were sizable, underlining the polarization Yushchenko faces as president.

Yushchenko’s spokeswoman Irina Herashenko said the visit to Moscow would be followed a day later by a trip to Strasbourg, France, to address the Parliamentary Assembly of the Council of Europe. He also plans to speak at the European Parliament. Yushchenko will visit the international economic forum in Davos, Switzerland.